App: [skip ci] add class PropertyListT

src/App/DocumentObserver.cpp

@@ -248,10 +248,8 @@ const std::string &DocumentObjectT::getPropertyName() const {
 std::string DocumentObjectT::getPropertyPython() const
 {
     std::stringstream str;
-    str << "FreeCAD.getDocument('" << document
-        << "').getObject('" << object
-        << "')";
-    if(property.size())
+    str << getObjectPython();
+    if (property.size())
         str << '.' << property;
     return str.str();
 }
@@ -400,6 +398,99 @@ std::vector<App::DocumentObject*> SubObjectT::getSubObjectList() const {
 
 // -----------------------------------------------------------------------------
 
+PropertyListT::PropertyListT()
+    : toPython("None")
+{
+}
+
+PropertyListT::PropertyListT(DocumentObject *obj)
+    : PropertyListT()
+{
+    if (obj) {
+        std::ostringstream str;
+        DocumentObjectT objT(obj);
+        str << objT.getObjectPython();
+
+        toPython = str.str();
+    }
+}
+
+PropertyListT::PropertyListT(DocumentObject *obj, const std::vector<std::string>& subNames)
+    : PropertyListT()
+{
+    if (obj) {
+        std::ostringstream str;
+        DocumentObjectT objT(obj);
+        str << "(" << objT.getObjectPython() << ",[";
+        for(const auto& it : subNames)
+            str << "'" << it << "',";
+        str << "])";
+
+        toPython = str.str();
+    }
+}
+
+PropertyListT::PropertyListT(const std::vector<DocumentObject*>& objs)
+    : PropertyListT()
+{
+    if (!objs.empty()) {
+        std::stringstream str;
+        str << "[";
+        for (std::size_t i = 0; i < objs.size(); i++) {
+            if (i > 0)
+                str << ", ";
+
+            App::DocumentObject* obj = objs[i];
+            if (obj) {
+                DocumentObjectT objT(obj);
+                str << objT.getObjectPython();
+            }
+            else {
+                str << "None";
+            }
+        }
+
+        str << "]";
+    }
+}
+
+PropertyListT::PropertyListT(const std::vector<DocumentObject*>& objs, const std::vector<std::string>& subNames)
+    : PropertyListT()
+{
+    if (!objs.empty() && objs.size() == subNames.size()) {
+        std::stringstream str;
+        str << "[";
+        for (std::size_t i = 0; i < subNames.size(); i++) {
+            if (i>0)
+                str << ",(";
+            else
+                str << "(";
+
+            App::DocumentObject* obj = objs[i];
+            if (obj) {
+                DocumentObjectT objT(obj);
+                str << objT.getObjectPython();
+            }
+            else {
+                str << "None";
+            }
+
+            str << ",";
+            str << "'" << subNames[i] << "'";
+            str << ")";
+        }
+
+        str << "]";
+    }
+}
+
+std::string PropertyListT::getPropertyPython() const
+{
+    return toPython;
+}
+
+// -----------------------------------------------------------------------------
+
 class DocumentWeakPtrT::Private {
 public:
     Private(App::Document* doc) : _document(doc) {

src/App/DocumentObserver.h

@@ -211,6 +211,34 @@ private:
     std::string subname;
 };
 
+/**
+ * The PropertyListT class is a helper class to create Python statements for proprty links.
+ */
+class AppExport PropertyListT
+{
+public:
+    /*! Constructor */
+    PropertyListT();
+
+    /*! Constructor */
+    PropertyListT(DocumentObject *obj);
+
+    /*! Constructor */
+    PropertyListT(DocumentObject *obj, const std::vector<std::string>& subNames);
+
+    /*! Constructor */
+    PropertyListT(const std::vector<DocumentObject*>& objs);
+
+    /*! Constructor */
+    PropertyListT(const std::vector<DocumentObject*>& objs, const std::vector<std::string>& subNames);
+
+    /*! Get the property as Python command. */
+    std::string getPropertyPython() const;
+
+private:
+    std::string toPython;
+};
+
 /**
  * @brief The DocumentWeakPtrT class
  */